In the manufacture of electronic devices such as semiconductor devices, a plasma processing apparatus is used to perform plasma processing, for example, plasma etching, on a workpiece. The plasma processing apparatus is provided with a chamber body, an electrode, a radio frequency power source, and a matching device. The chamber body provides an internal space thereof as a chamber. The electrode is an electrode for generation of plasma or generation of a bias in the chamber. The radio frequency power source generates a radio frequency wave. The radio frequency power source is connected to the electrode through the matching device. The matching device has a circuit for matching the output impedance of the radio frequency power source and the impedance of a load.
A circuit of the matching device which is used in the plasma processing apparatus generally has a variable capacitor capable of mechanically changing a capacitance. Such a variable capacitor cannot change the capacitance at high speed. Therefore, the matching device cannot perform a high-speed matching operation. As a measure for realizing a high-speed matching operation of the matching device, a technique of using a field-effect transistor instead of a variable capacitor is disclosed in Patent Literature 1.